2 files changed, 32 insertions, 1 deletions
diff --git a/packages/connect/src/utils/assert.ts b/packages/connect/src/utils/assert.ts
new file mode 100644
index 000000000..f8241aacb
--- /dev/null
+++ b/packages/connect/src/utils/assert.ts
@@ -0,0 +1,25 @@
+import { assert as sharedAssert } from '@0xproject/assert';
+// We need those two unused imports because they're actually used by sharedAssert which gets injected here
+// tslint:disable-next-line:no-unused-variable
+import { Schema, schemas } from '@0xproject/json-schemas';
+// tslint:disable-next-line:no-unused-variable
+import { ECSignature } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+import * as _ from 'lodash';
+
+export const assert = {
+    ...sharedAssert,
+    isOrderbookChannelSubscriptionOpts(variableName: string, subscriptionOpts: any): void {
+        sharedAssert.doesConformToSchema(
+            'subscriptionOpts',
+            subscriptionOpts,
+            schemas.relayerApiOrderbookChannelSubscribePayload,
+        );
+    },
+    isOrderbookChannelHandler(variableName: string, handler: any): void {
+        sharedAssert.isFunction(`${variableName}.onSnapshot`, _.get(handler, 'onSnapshot'));
+        sharedAssert.isFunction(`${variableName}.onUpdate`, _.get(handler, 'onUpdate'));
+        sharedAssert.isFunction(`${variableName}.onError`, _.get(handler, 'onError'));
+        sharedAssert.isFunction(`${variableName}.onClose`, _.get(handler, 'onClose'));
+    },
+};
diff --git a/packages/connect/src/utils/orderbook_channel_message_parser.ts b/packages/connect/src/utils/orderbook_channel_message_parser.ts
index 9a9ca8901..593288078 100644
--- a/packages/connect/src/utils/orderbook_channel_message_parser.ts
+++ b/packages/connect/src/utils/orderbook_channel_message_parser.ts
@@ -8,10 +8,16 @@ import { relayerResponseJsonParsers } from './relayer_response_json_parsers';
 
 export const orderbookChannelMessageParser = {
     parse(utf8Data: string): OrderbookChannelMessage {
+        // parse the message
         const messageObj = JSON.parse(utf8Data);
+        // ensure we have a type parameter to switch on
         const type: string = _.get(messageObj, 'type');
         assert.assert(!_.isUndefined(type), `Message is missing a type parameter: ${utf8Data}`);
         assert.isString('type', type);
+        // ensure we have a request id for the resulting message
+        const requestId: number = _.get(messageObj, 'requestId');
+        assert.assert(!_.isUndefined(requestId), `Message is missing a requestId parameter: ${utf8Data}`);
+        assert.isNumber('requestId', requestId);
         switch (type) {
             case OrderbookChannelMessageTypes.Snapshot: {
                 assert.doesConformToSchema('message', messageObj, schemas.relayerApiOrderbookChannelSnapshotSchema);
@@ -28,7 +34,7 @@ export const orderbookChannelMessageParser = {
             default: {
                 return {
                     type: OrderbookChannelMessageTypes.Unknown,
-                    requestId: 0,
+                    requestId,
                     payload: undefined,
                 };
             }